Buckling of Porcine Aorta Under Static and Dynamic Loading

2012 ◽  
Author(s):  
Mobin Rastgar Agah ◽  
Kaveh Laksari ◽  
Kurosh Darvish ◽  
Alexander Rachev
Keyword(s):  
Blood Vessels ◽  
Dynamic Loading ◽  
Motor Vehicle ◽  
Vascular System ◽  
Experimental Studies ◽  
Dynamic Buckling ◽  
Traumatic Rupture ◽  
Buckling Behavior ◽  
Static And Dynamic Loading ◽  
Original Configuration

Tortuosity and buckling of blood vessels are defined as the deviation from original configuration and has been observed throughout the vascular system. The blood flow in the regions down-stream of tortuous section decreases, which may cause a deficiency in blood supply to the organs and ischemia. Although tortuosity of blood vessels has been associated with aging, atherosclerosis, hypertension, genetic and other cardiovascular disease, the mechanism behind its initiation and development is not yet understood. In a series of theoretical and experimental studies, biomechanical aspects of buckling of arteries has been investigated under quasi-static loading (Han, 2007; Liu and Han, 2011); however, it has been shown theoretically that the buckling behavior of arteries under dynamic loading are different and arteries may become mechanically unstable at pressures other than the static critical loading (Rachev, 2009). This work addresses buckling of porcine aorta and experimental verification of dynamic buckling in this case. We hypothesize that dynamic buckling can partly contribute to the traumatic rupture of aorta that is a leading cause of fatality in motor vehicle crashes.

Impact Behaviour of Small Scale Model Motor Coaches

1972 ◽  
Vol 186 (1) ◽  
pp. 409-419 ◽  
Author(s):  
W. T. Lowe ◽  
S. T. S. Al-Hassani ◽  
W. Johnson
Keyword(s):  
Dynamic Loading ◽  
Motor Vehicle ◽  
Scale Model ◽  
Small Scale ◽  
Tubular Structures ◽  
Dimensionless Analysis ◽  
Theoretical Approaches ◽  
Vehicle Collision ◽  
Static And Dynamic Loading ◽  
Small Scale Model

Simplified small scale model motor coaches were designed and tested under both static and dynamic loading and attempts are made to relate the results to a full scale collision. Two theoretical approaches for the modelling of a motor vehicle collision are discussed and generally developed using dimensionless analysis and a technique of relating the actual vehicle and models to tubular structures.

scholarly journals EXPERIMENTAL STUDY OF PLATES FOR PUNCHING UNDER DYNAMIC LOADING

2021 ◽  
Vol 4 (4) ◽  
pp. 41-48
Author(s):  
N. Trekin ◽  
D. Sarkisov ◽  
V. Krylov ◽  
E. Evstaf'eva ◽  
K. Andryan
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Static Load ◽  
Dynamic Testing ◽  
Experimental Studies ◽  
Breaking Load ◽  
Technical Literature ◽  
Failure Patterns ◽  
Static And Dynamic Loading

the issues of strength and deformability of reinforced concrete floors during punching remain insufficiently studied at present, despite the available publications in the technical literature. This article presents the results of experimental studies on punching of fragments of conjugation of flat reinforced concrete monolithic slabs with a column under dynamic loading. The purpose of these studies was to obtain experimental data on the stress-strain state of a fragment of a monolithic floor during dynamic punching with varying thickness and class of concrete, to reveal the failure patterns of experimental samples, and to obtain new experimental data. A setup for dynamic testing is described. Comparison of breaking load for specimens tested under dynamic loading with breaking load for specimens tested for static load is presented. The angles of inclination of the punching shear pyramid under static and dynamic loading are indicated.

scholarly journals COMPARISON OF NECK MUSCLE ELECTROMYOGRAPHY ACTIVITY IN RESPONSE TO EXTERNAL FORCE BETWEEN STATIC AND DYNAMIC LOADING

2019 ◽  
Vol 19 (04) ◽  
pp. 1850034
Author(s):  
D. W. KAK ◽  
A. R. ANITA ◽  
N. M. NIZLAN ◽  
I. NORMALA ◽  
N. A. ABDUL JALIL ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Static Loading ◽  
Muscle Activation ◽  
Motor Vehicle ◽  
Neck Muscles ◽  
Motor Vehicle Crash ◽  
Neck Muscle ◽  
Activation Level ◽  
Static And Dynamic Loading ◽  
Head Neck

Understanding the behavior of neck muscles is essential to accurately simulate the human head-neck segment movement especially for low-speed motor vehicle crash situation. Some head-neck mathematical models were designed using neck muscle activation behavior in isometric contraction (static loading) as the properties of neck muscle activation. However, neck muscle activation pattern and strength capability may vary between static and dynamic loading. This study aimed to determine the differences between neck muscle activation level under static and dynamic loading. A neck strength test involving 22 human volunteers was conducted with two different tasks in extension and flexion direction with three different loads. The neck muscle activation level is determined through measuring the electromyography (EMG) responses of selected flexor and extensor muscles using surface bilateral electrode and recorded. The findings showed that neck muscle activation level was significantly greater in dynamic loading than static loading ([Formula: see text]). These implied that more efforts from neck muscles were required to resist against dynamic loading than static loading. Nonetheless, the differences in EMG activities between these two loading conditions progressively decreased when more loads were applied. This study has established an empirical model to describe the relationship between neck muscle activation level and force output for both loading condition in flexion and extension.

Microfluidics of blood in blood vessels stenosis

2016 ◽  
Vol 11 (2) ◽  
pp. 210-217 ◽  
Author(s):  
A.T. Akhmetov ◽  
A.A. Valiev ◽  
A.A. Rakhimov ◽  
S.P. Sametov ◽  
R.R. Habibullina
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Hydraulic Resistance ◽  
Microfluidic Device ◽  
Human Body ◽  
Vascular System ◽  
Hydrodynamic Conditions ◽  
Microstructure Change ◽  
Healthy Part

It is mentioned in the paper that hydrodynamic conditions of a flow in blood vessels with the stenosis are abnormal in relation to the total hemodynamic conditions of blood flow in a vascular system of a human body. A microfluidic device developed with a stepped narrowing for studying of the blood flow at abnormal conditions allowed to reveal blood structure in microchannels simulating the stenosis. Microstructure change is observed during the flow of both native and diluted blood through the narrowing. The study of hemorheological properties allowed us to determine an increasing contribution of the hydraulic resistance of the healthy part of the vessel during the stenosis formation.

scholarly journals Formation of the Traffic Flow Rate under the Influence of Traffic Flow Concentration in Time at Controlled Intersections in Tyumen, Russian Federation

2021 ◽  
Vol 13 (15) ◽  
pp. 8324
Author(s):  
Viacheslav Morozov ◽  
Sergei Iarkov
Keyword(s):  
Traffic Flow ◽  
Flow Rate ◽  
Traffic Congestion ◽  
Traffic Management ◽  
System Analysis ◽  
Motor Vehicle ◽  
Experimental Studies ◽  
Transport Systems ◽  
Experiment Planning ◽  
Traffic Light

Present experience shows that it is impossible to solve the problem of traffic congestion without intelligent transport systems. Traffic management in many cities uses the data of detectors installed at controlled intersections. Further, to assess the traffic situation, the data on the traffic flow rate and its concentration are compared. Latest scientific studies propose a transition from spatial to temporal concentration. Therefore, the purpose of this work is to establish the regularities of the influence of traffic flow concentration in time on traffic flow rate at controlled city intersections. The methodological basis of this study was a systemic approach. Theoretical and experimental studies were based on the existing provisions of system analysis, traffic flow theory, experiment planning, impulses, probabilities, and mathematical statistics. Experimental data were obtained and processed using modern equipment and software: Traficam video detectors, SPECTR traffic light controller, Traficam Data Tool, SPECTR 2.0, AutoCad 2017, and STATISTICA 10. In the course of this study, the authors analyzed the dynamics of changes in the level of motorization, the structure of the motor vehicle fleet, and the dynamics of changes in the number of controlled intersections. As a result of theoretical studies, a hypothesis was put forward that the investigated process is described by a two-factor quadratic multiplicative model. Experimental studies determined the parameters of the developed model depending on the directions of traffic flow, and confirmed its adequacy according to Fisher’s criterion with a probability of at least 0.9. The results obtained can be used to control traffic flows at controlled city intersections.

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